Cost-effectiveness of nidotherapy for comorbid personality disorder and severe mental illness: randomized controlled trial.

Aims: Nidotherapy is the systematic modification of the environment to create a better fit for people. This is the first randomized controlled trial of its efficacy in an assertive community team.

Methods: Patients in an assertive outreach team with continued management problems together with comorbid personality disturbance and severe mental illness were randomized to nidotherapy enhanced assertive treatment (up to 12 sessions) or to continued assertive outreach care.